The present invention relates to an apparatus and method of achieving a fusion propulsion engine as could be used by a starship that is both highly efficient and is capable of achieving very high fuel specific impulse. The invention also relates to the use of said basic engine as a generator for supplying very large amount of power in the form of heat that can then be converted to electrical energy by use of conventional steam turbogenerators.
The search for controlled fusion has been a major scientific effort for many years. The major thrust has been directed at the brute force approach of heating a gaseous mixture (usually deuterium and tritium) in the form of a plasma (ionized gas) to sufficient temperature and pressure and then holding this state for sufficient time to allow the nuclei of the mixture to collide and thus fuse with the liberation of energy. Despite the expenditures of vast sums of money and effort, this approach has yet to achieve a "breakeven" condition as defined by the point at which the amount of energy being produced is equal to the amount of input energy. The "breakeven" condition, assuming it can eventually be achieved by the plasma "ohmic heating approach" would represent only about 1% of the available fusion energy being realized and with 99% being lost.
The major difficulty with the plasma heating approach has been that the only way to contain the plasma during the heating phase is with magnetic fields. The plasma has, so far, always been able to exhibit some form of instability that has prevented the magnetic fields from being able to contain the heated, ionized gas for sufficient time to even reach the breakeven point in energy production. The present prediction is that it will be at least 40 years before this approach can be expected to produce useful energy. The production of useful energy is estimated to require a fusion energy output at least 10 times the breakeven point. It may also be true that this approach will never work in terms of producing useful energy from a fusion process.
In the late '60s another approach was given serious consideration in an attempt to solve the controlled fusion problem. This approach involved the creation of a potential well through which ionized particles (again notably deuterium and tritium, the D-T reaction) were made to osillate at high relative energies and thus occasionally experience a head-on collision that resulted in fusion. The best example of this approach is contained in a paper by Dr. R. L. Hirsch (Inertial-Electrostatic Confinement of Ionized Fusion Gases, J. Appl. Phys. 38, No. 11, 4522-4534, 1967) in which it was reported that significant neutrons (the product of a D-T fusion reaction) were detected from the apparatus as described in the article. It is believed that the approach was abandoned, however, as it did not appear that it could lead to the generation of useful amounts of energy. Its major problem was that the maximum relative ion energy occurring at the center of the potential well was also the point of minimum density. The low density at the well's center prevented appreciable fusion reactions from occurring.